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From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Mark Rutland <mark.rutland@arm.com>, Andrew Lunn <andrew@lunn.ch>,
	Jason Cooper <jason@lakedaemon.net>,
	devicetree@vger.kernel.org, Stephen Boyd <sboyd@kernel.org>,
	linux-pci@vger.kernel.org,
	Gregory Clement <gregory.clement@bootlin.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	linux-kernel@vger.kernel.org,
	Maxime Chevallier <maxime.chevallier@bootlin.com>,
	Nadav Haklai <nadavh@marvell.com>,
	Antoine Tenart <antoine.tenart@bootlin.com>,
	Rob Herring <robh+dt@kernel.org>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	sudeep.holla@arm.com, Bjorn Helgaas <bhelgaas@google.com>,
	linux-arm-kernel@lists.infradead.org,
	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Subject: Re: [PATCH 05/12] PCI: aardvark: add suspend to RAM support
Date: Thu, 13 Dec 2018 14:52:25 +0000	[thread overview]
Message-ID: <20181213145225.GA28015@red-moon> (raw)
In-Reply-To: <20181213153000.245d7d5f@xps13>

On Thu, Dec 13, 2018 at 03:30:00PM +0100, Miquel Raynal wrote:
> Hi Lorenzo,
> 
> > > If that's really the case, then I can see how one device and it's
> > > children are suspended and the irq for it is disabled but the providing
> > > devices (clk, regulator, bus controller, etc.) are still fully active
> > > and not suspended but in fact completely usable and able to service
> > > interrupts. If that all makes sense, then I would answer the question
> > > with a definitive "yes it's all fine" because the clk consumer could be
> > > in the NOIRQ phase of its suspend but the clk provider wouldn't have
> > > even started suspending yet when clk_disable_unprepare() is called.  
> > 
> > That's a very good summary and address my concern, I still question this
> > patch correctness (and many others that carry out clk operations in S2R
> > NOIRQ phase), they may work but do not tell me they are rock solid given
> > your accurate summary above.
> 
> I understand your concern but I don't see any alternative right now
> and a deep rework of the PM core to respect such dependency is not
> something that can be done in a reasonable amount of time. With
> regard to this constraint, do you think it is worth blocking the
> series?

I think we agree that, depending on what HW/SW driver manage
this PCI controller clocks, this driver may well become broken,
the driver itself has no idea what's behind the clock API and
can end up waiting for an event forever.

This does not leave me in a comfortable position to merge code that I
know has flaws.

I won't merge it for v4.21, I need more time (and feedback) to
understand what can be done to make this driver (and many others)
more robust.

Thanks,
Lorenzo

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  reply	other threads:[~2018-12-13 14:52 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-23 14:18 [PATCH 00/12] Bring suspend to RAM support to PCIe Aardvark driver Miquel Raynal
2018-11-23 14:18 ` [PATCH 01/12] PCI: aardvark: configure more registers in the configuration helper Miquel Raynal
2018-11-23 14:18 ` [PATCH 02/12] PCI: aardvark: add reset GPIO support Miquel Raynal
2018-11-23 14:18 ` [PATCH 03/12] PCI: aardvark: add PHY support Miquel Raynal
2018-11-23 14:18 ` [PATCH 04/12] PCI: aardvark: add clock support Miquel Raynal
2018-11-23 14:18 ` [PATCH 05/12] PCI: aardvark: add suspend to RAM support Miquel Raynal
2018-12-03 10:27   ` Lorenzo Pieralisi
2018-12-03 15:38     ` Miquel Raynal
2018-12-03 17:18       ` Lorenzo Pieralisi
2018-12-03 19:19         ` Stephen Boyd
2018-12-03 22:00       ` Rafael J. Wysocki
2018-12-03 22:18         ` Miquel Raynal
2018-12-04  9:45         ` Lorenzo Pieralisi
2018-12-04 21:42           ` Rafael J. Wysocki
2018-12-05 11:00             ` Lorenzo Pieralisi
2018-12-11 14:16             ` Lorenzo Pieralisi
2018-12-13  9:00               ` Stephen Boyd
2018-12-13 10:53                 ` Lorenzo Pieralisi
2018-12-13 14:30                   ` Miquel Raynal
2018-12-13 14:52                     ` Lorenzo Pieralisi [this message]
2018-12-13 21:50                     ` Rafael J. Wysocki
2018-12-17 14:54                       ` Miquel Raynal
2018-12-18 10:54                         ` Rafael J. Wysocki
2018-12-18 14:14                           ` Miquel Raynal
2018-11-23 14:18 ` [PATCH 06/12] dt-bindings: PCI: aardvark: describe the reset-gpios property Miquel Raynal
2018-12-11 21:44   ` Rob Herring
2018-11-23 14:18 ` [PATCH 07/12] dt-bindings: PCI: aardvark: describe the clocks property Miquel Raynal
2018-12-11 21:44   ` Rob Herring
2018-11-23 14:18 ` [PATCH 08/12] dt-bindings: PCI: aardvark: describe the PHY property Miquel Raynal
2018-12-11 21:44   ` Rob Herring
2018-11-23 14:18 ` [PATCH 09/12] ARM64: dts: marvell: armada-37xx: declare PCIe reset pin Miquel Raynal
2018-11-23 14:18 ` [PATCH 10/12] ARM64: dts: marvell: armada-3720-espressobin: declare PCIe reset GPIO Miquel Raynal
2018-11-23 14:18 ` [PATCH 11/12] ARM64: dts: marvell: armada-37xx: declare PCIe clock Miquel Raynal
2018-11-23 14:18 ` [PATCH 12/12] ARM64: dts: marvell: armada-3720-espressobin: declare PCIe PHY Miquel Raynal
2018-11-26 14:50 ` [PATCH 00/12] Bring suspend to RAM support to PCIe Aardvark driver Bjorn Helgaas
2018-11-30 13:12   ` Miquel Raynal

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